Disable scheduler deadline task on battery power in Windows

cc/scheduler/scheduler_state_machine.cc

Index: cc/scheduler/scheduler_state_machine.cc
diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index 74a4f0679f1adb7710278ef4a0bf32171e3db05a..e61d36db63edd32736caa191b4b33090ab4c12a2 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -48,7 +48,8 @@ SchedulerStateMachine::SchedulerStateMachine(const SchedulerSettings& settings)
       impl_latency_takes_priority_(false),
       skip_next_begin_main_frame_to_reduce_latency_(false),
       skip_begin_main_frame_to_reduce_latency_(false),
-      continuous_painting_(false) {
+      continuous_painting_(false),
+      impl_latency_takes_priority_on_battery_(false) {
 }
 
 const char* SchedulerStateMachine::OutputSurfaceStateToString(
@@ -238,6 +239,8 @@ void SchedulerStateMachine::AsValueInto(base::debug::TracedValue* state,
   state->SetBoolean("skip_next_begin_main_frame_to_reduce_latency",
                     skip_next_begin_main_frame_to_reduce_latency_);
   state->SetBoolean("continuous_painting", continuous_painting_);
+  state->SetBoolean("impl_latency_takes_priority_on_battery",
+                    impl_latency_takes_priority_on_battery_);
   state->EndDictionary();
 }
 
@@ -879,6 +882,11 @@ bool SchedulerStateMachine::ShouldTriggerBeginImplFrameDeadlineEarly() const {
   if (impl_latency_takes_priority_)
     return true;
 
+  // If we are on battery power and want to prioritize impl latency because
+  // we don't trust deadline tasks to execute at the right time.
+  if (impl_latency_takes_priority_on_battery_)
+    return true;
+
   return false;
 }